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img crit density
immage critique - density
Question | Answer |
---|---|
Film density | the degree of overall blackening from the black metallic silver deposited in the emulsion |
Window level | digital processing that produces changes in density/brightness |
In CR and DR “density” refers to: | image density or brightness |
What is the controlling factor of density for screen film? | mAs |
What is the controlling factor of density in digital? | window level |
What does mAs control in digital? | it assures proper exposure of the IR |
What change in mAs is necessary to produce a visible change in density on screen film? | 30% |
How should changes in mAs be determined? | mAs should always be doubled of halved |
FSS can affect density how on an improperly calibrated machine? | 30% increase |
Anode heel effect is what? | 45% greater density on the cathode side of the tube |
How are filtration and density related? | inversely |
Increased tissue thickness affects density how? | increased scatter increases overall density |
Increase in atomic number (Z | ) affects density how? |
Distance and intensity are related how? | ½ distance = ¼ intensity |
“density maintenance formula”? | direct square law |
Beam restriction and density are related how? | inversely |
How are scatter and density related? | increased scatter increases overall film density, any factor increasing scatter increases density. |
Additive pathology and density | additive pathologies are radiopaque, decreasing overall film density. |
Destructive pathology and density | destructive pathologies are radiolucent , increasing overall film density |